diff --git a/src/index.js b/src/index.js
index 3955b16..b94ea26 100644
--- a/src/index.js
+++ b/src/index.js
@@ -91,6 +91,7 @@ module.exports = {
     'no-lonely-if': 'error',
     'no-loop-func': 'error',
     'no-mixed-requires': 'error',
+    'no-mixed-spaces-and-tabs': 'error',
     'no-multi-spaces': 'error',
     'no-multi-str': 'error',
     'no-multiple-empty-lines': ['error', {
diff --git a/test/fixtures/environment.js b/test/fixtures/environment.js
index b771ae2..3f4cc19 100644
--- a/test/fixtures/environment.js
+++ b/test/fixtures/environment.js
@@ -9,9 +9,9 @@ function noop() {
 
 // `no-mixed-spaces-and-tabs`.
 function noMixedSpacesAndTabs() {
-	  const foo = 'bar';
+  const foo = 'bar';
 
-		noop(foo);
+ 	noop(foo);
 }
 
 noop(noMixedSpacesAndTabs);
diff --git a/test/fixtures/incorrect.js b/test/fixtures/incorrect.js
index f3dbd7d..4ac3855 100644
--- a/test/fixtures/incorrect.js
+++ b/test/fixtures/incorrect.js
@@ -7,7 +7,7 @@ function noop() {
 noop([ 'bar', 'foo']);
 
 // `arrow-parens`
-noop((foo) => {});
+noop((foo) => noop(foo));
 
 // `brace-style`.
 try {
@@ -25,7 +25,7 @@ noop(['bar','foo']);
 
 // `comma-style`.
 noop({
-    bar: 'foo'
+  bar: 'foo'
   , foo: 'bar'
 });
 
@@ -38,7 +38,7 @@ noop(consistentThis);
 let curly = true;
 
 if (curly)
-  curly = false
+  curly = false;
 
 // `dot-notation`.
 const dotNotation = {};
@@ -55,6 +55,11 @@ let id_match;
 
 noop(id_match);
 
+// `indent`.
+noop({
+    bar: 'foo'
+});
+
 // `key-spacing`.
 noop({ foo:'bar' });
 
@@ -72,7 +77,8 @@ describe.only('noExclusiveTests', () => {
 
 // `new-cap`.
 const cap = require('cap');
-const newCap = new cap();
+
+new cap();
 
 // `newline-after-var`.
 const newLineAfterVar = 'foo';
@@ -100,6 +106,8 @@ const noConstAssign = true;
 
 noConstAssign = false;
 
+noop(noConstAssign);
+
 // `no-constant-condition`.
 if (true) {
   noop(true);
@@ -123,17 +131,18 @@ try {
   noop();
 } catch (e) {}
 
-// `no-labels`.
-noLabels:
-  while (noLabels) {
-    break noLabels;
-  }
+// `no-labels` and `no-unused-labels`.
+noLabels: {
+  break noLabels;
+}
 
 // `no-mixed-spaces-and-tabs`.
-const noMixedSpacesAndTabs = {
-  bar: 'foo',
-  foo: 'bar'
-};
+noop({
+  foo: {
+    bar: 'foo',
+  	foo: 'bar'
+  }
+});
 
 // `no-multi-spaces`.
 noop(['foo',  'bar']);
@@ -168,18 +177,14 @@ noop(Child);
 // `no-underscore-dangle`.
 class NoUnderscoreDangle {
   constructor() {
-    this._foo = 'bar';
+    this._foo();
   }
 }
 
-const noUnderscoreDangle1 = { _foo: 'bar' };
-const noUnderscoreDangle2 = {};
-
-noUnderscoreDangle2._foo = 'bar';
+noop(new NoUnderscoreDangle());
 
-noop(NoUnderscoreDangle);
-noop(noUnderscoreDangle1);
-noop(noUnderscoreDangle2);
+// `no-unused-vars`
+const foobar = '';
 
 // `object-curly-spacing`.
 const objectCurlySpacing = {foo: 'bar'};
@@ -193,10 +198,10 @@ noop(oneVar1);
 noop(oneVar2);
 
 // `one-var-declaration-per-line`.
-const oneVar1 = 'foo'; const oneVar2 = 'bar';
+const oneVarDeclarationPerLine1 = 'foo'; const oneVarDeclarationPerLine2 = 'bar';
 
-noop(oneVar1);
-noop(oneVar2);
+noop(oneVarDeclarationPerLine1);
+noop(oneVarDeclarationPerLine2);
 
 // `operator-linebreak`.
 const operatorLineBreak = 1 +
@@ -260,7 +265,7 @@ let spaceBeforeBlocks = true;
 
 if (spaceBeforeBlocks){
   spaceBeforeBlocks = false;
-}else{
+} else {
   spaceBeforeBlocks = true;
 }
 
diff --git a/test/index.js b/test/index.js
index f0021b5..1411c89 100644
--- a/test/index.js
+++ b/test/index.js
@@ -23,18 +23,19 @@ describe('eslint-config-seegno', () => {
   it('should generate violations for environment-specific rules', () => {
     const source = path.join(__dirname, 'fixtures', 'environment.js');
 
-    linter.executeOnFiles([source]).results[0].messages.map(violation => violation.ruleId).should.containDeep([
-      'eol-last',
+    Array.from(new Set(linter.executeOnFiles([source]).results[0].messages.map(violation => violation.ruleId))).should.eql([
       'linebreak-style',
-      'no-mixed-spaces-and-tabs'
+      'no-mixed-spaces-and-tabs',
+      'eol-last'
     ]);
   });
 
   it('should generate violations for incorrect code', () => {
     const source = path.join(__dirname, 'fixtures', 'incorrect.js');
 
-    linter.executeOnFiles([source]).results[0].messages.map(violation => violation.ruleId).should.containDeep([
+    Array.from(new Set(linter.executeOnFiles([source]).results[0].messages.map(violation => violation.ruleId))).should.eql([
       'array-bracket-spacing',
+      'arrow-parens',
       'brace-style',
       'comma-dangle',
       'comma-spacing',
@@ -42,10 +43,13 @@ describe('eslint-config-seegno', () => {
       'consistent-this',
       'curly',
       'dot-notation',
+      'generator-star-spacing',
       'id-match',
+      'indent',
       'key-spacing',
       'keyword-spacing',
       'mocha/no-exclusive-tests',
+      'no-new',
       'new-cap',
       'newline-after-var',
       'newline-before-return',
@@ -55,12 +59,14 @@ describe('eslint-config-seegno', () => {
       'no-dupe-class-members',
       'no-empty',
       'no-labels',
+      'no-mixed-spaces-and-tabs',
       'no-multi-spaces',
       'no-multi-str',
       'no-multiple-empty-lines',
       'no-spaced-func',
       'no-this-before-super',
       'no-underscore-dangle',
+      'no-unused-vars',
       'object-curly-spacing',
       'one-var',
       'one-var-declaration-per-line',